Hydrothermal Synthesis and Characterization of a Sandwich-type Tungstophosphate,(1,3-H2dap)8H4Co4(H2O)2(α-B-PW9O34)2 2·5H2O

摘要

A sandwich-type tungstophosphate, (1,3-H_2dap)_8H_4[Co_4(H_2O)_2(α-B- PW_9O_(34))_2]_2·5H_2O (1,3-dap = 1,3-diaminopropane), was hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, IR and UV spectroscopy. The title compound crystallizes in triclinic, space group P1 with a = 13.691(3), b = 17.744(4), c = 20.620(5), α =113.466(5), β = 91.184(5), γ = 104.223(5)°, V = 4414.3(17)~3, C_(24)H_(96)Co_8N_(16)O_(145)P_4W_(36), M_r = 10143.09, D_c = 3.816 g/cm^3, μ(MoKα) = 24.210 mm^(-1), F(000) = 4452, Z = 1, the final R = 0.0694 and wR = 0.1519 for 9910 observed reflections (I > 2σ(I)). The compound consists of two sets of tetra-transition metal-substituted sandwich frameworks, [Co_4(H_2O)_2(α-B-PW_9O_(34))_2]^(10-) having an inversion centre. Two lacunary α-B-[PW_9O_(34)]^(9-) Keggin units are linked by a rhomb-like Co_4O_(14)(H_2O)_2 cluster, in which the Co^(2+) ions are coordinated by one water molecule. Isolatedly protonated 1,3-H2dap^(2+) units act as counter-ions to interact with the [Co_4(H_2O)_2(α-B-PW_9O_(34))_2]^(10-) heteropolyanions via hydrogen bonds, resulting in a three-dimensional framework.